深井高瓦斯工作面“一巷多用”瓦斯治理新模式

New comprehensive gas control mode based on one roadway with multipurposes of high methane working face in deep coal mine

埋深超过900 m的深井高瓦斯工作面瓦斯治理一直是世界性难题。针对千米深井1112(1)工作面(最大瓦斯涌出量为124.87 m3/min)的实际条件,通过相似材料模拟实验,确定了位于开采煤层顶板上方10倍采高、水平方向内错沿空留巷侧约20 m开始存在宽度为30 m的扇形环状瓦斯富集区,该高度采动影响范围沿倾向外错轨道巷最大不超过30 m。基于此,在上距顶板20 m,外错轨道巷35 m处布置一条多用巷,提出"一面三巷、一巷多用、联合治理、连续开采"瓦斯治理新模式。工程实践表明,多用巷内大直径穿层钻孔单孔抽采瓦斯纯量最大达9.84 m3/min,瓦斯浓度最高为98.5%,工作面瓦斯抽采率最高为92.4%,回风流瓦斯浓度平均0.4%,日产原煤量最高为10 324.6 t,抽采瓦斯总量为2 457.2万m3,实现了深井煤与瓦斯的安全高效共采。

Comprehensive gas control of high methane working face in more than 900 m depth has always been a worldwide problem. An similar material simulation experiment was carried out based on the geological conditions of1112( 1) face in a kilometer deep coal mine,where the maximum gas emission quantity was 124.87 m3/ min. The results show that a gas enrichment area,which is fan-shaped ring zone with a width of 30 m,exists and is located at 10 times mining height from the roof of mined coal seam in the vertical direction and starts from 20 m between the gobside roadway in the horizontal direction,and the stress variation range along the coal seam by mining is not more than30 m out of the track roadway at 10 times mining height. Therefore,the multi-purposes roadway was constructed at about 20 m higher than the roof strata and about 35 m outside the track roadway.And then the new comprehensive gas control mode including three lanes with a face,one roadway with multi-purposes,joint control and continuous mining was put forward.Engineering practice indicated that the maximum of methane extraction amount and the concentration of single penetrating borehole was 9. 84 m3/ min and 98. 5% respectively,the maximal gas drainage efficiency was92. 4%,the average volume fraction of gas in return airflow was 0.4%,the maximal output of coal was 10 324.6 t / d and the total gas extraction quantity is 24.572 million m3.The mode proposed can achieve a safe and efficient simulta-neous mining of coal and gas.